基于太赫兹超表面实现表面波的自旋解耦和波前整形的研究

Research on Spin Decoupling and Wavefront Shaping of Surface Waves Based on Terahertz Metasurface

摘要: 为了实现表面波(Surface wave)的激发和自旋解耦的波前整形，设计了一种基于几何相位和传播相位的超表面器件。该器件由两部分组成：左右两侧是金属，中间是I字型的单元结构。使用几何相位和传播相位相结合的波前调控方式，结合CST仿真软件，对超表面器件进行数值仿真。研究结果表明，通过设计单元的几何尺寸和旋转角度，可以确定使左旋圆偏光和右旋圆偏光解耦的相位分布，实现自由调控的焦点、光线的偏折和贝塞尔光束。相关研究有利于设计太赫兹(THz)集成光子器件和系统。

Abstract: To achieve the excitation of surface waves and spin-decoupled wavefront shaping, a metadevice based on geometric and propagation phases is designed. The device consists of two parts: metamaterial units (located at the center) and plasmonic metals (on the left and right sides). By employing the wavefront modulation approach combining geometric and propagation phases, numerical simulations of the metadevice are conducted based on CST software. The research findings indicate that by designing the geometric dimensions and rotation angles of the units, the independent phase distribution of left-circularly polarized and right-circularly polarized light can be achieved, which enables flexible control of focal points, beam deflection, and Bessel beams. This research contributes to the design of THz integrated photonic devices and systems.